1. Field
One embodiment of the invention relates to an image processing technology, and more particularly, to an image processing apparatus, a receiver, and display device.
2. Description of the Related Art
In recent years, as the resolution of images has been increasing, the resolution of display panels such as liquid crystal display (LCD) panels has also been increasing. Thus, there are now display panels with a resolution of, for example, 3840×2160 pixels that is higher than full high definition (HD).
Japanese Patent Application Publication (KOKAI) No. H11-119722 discloses a conventional technology for enabling a still image with a high resolution of 2048×1536 pixels to be displayed on a display device even if the graphics card can render images of up to 1024×768 resolution. With the conventional technology, an input still image is once divided into four still images with a resolution of 1024×768 pixels. After that, the still images are combined together to be displayed on the display device. Thus, the high-resolution still image can be displayed on the display device.
When a moving image is displayed with a higher resolution than full HD, the moving image is generally expanded by scaling. Therefore, in the strict sense, it is not that the moving image is displayed with a higher resolution than full HD.
When, as in the case of a television receiver, a still image and a moving image received from the outside is displayed on an LCD panel or the like, scaling is performed on the still image as well as the moving image. For example, if a receiver that receives images such as a still image and a moving image from the outside is configured to be separated from a display device such as an LCD panel that displays the still image and the moving image received by the receiver, as, for example, a set-top box and an LCD panel, these devices are connected by a cable compatible with high-definition multimedia interface (HDMI). Thus, the receiver transmits the still image with the same resolution as the moving image to the display device. Then, the images are displayed on the display device after scaling is performed on them.
Differently from a moving image, with regard to a still image such as an electronic program guide (EPG), the receiver can generate still images of various resolutions. That is, in a physical sense, it is possible to generate a still image with a higher resolution than full HD.
With the cable compatible with HDMI, however, the maximum resolution of an image that can be transmitted is full HD. Consequently, a still image with a higher resolution than full HD cannot be transmitted as it is. As a result, a still image with a resolution of up to full HD can only be displayed in practice.